What would be an example of a green where as long as you can get a decent amount of club on the ball you don't mind where you approach it from?
It is hard to think of interesting greens where; your stance, angle of attack, whether slopes of the green work with/against you, your shop shape preference, your position relative to greenside hazards, availability of ground game etc do not come into how you would like to play the hole. As soon as you work backwards from the green and any of the features above come into your mind then the positioning of your drive is important. I understand that we are saying the second shot is the emphasis of the hole and not that the drive means nothing but I find it hard to separate the two if the green presents numerous unequal options.
If this is the case, it seems like ANGC, seminole, st andrews beach and pinehurst are more than second shot courses. I just feel there must be a strong correlation between interest/challenge of the greensite and the importance of the drive.
Even if angles of attack are limited (small greens maybe?), you would surely like to hit in with a short iron rather than a long iron?
Give me a choice between hitting a short iron and a long iron into a green and I'll tell you that as long as you're giving a choice, I'd prefer to be putting it from the fringe.
Length is its own reward, that goes without saying. I think there's an inherent assumption that courses that require more out of a player off the tee are requiring more accuracy off the tee in placing the ball where you maximize the chance of success for your approach, rather than simply hitting the ball further to leave a shorter club. The former is a skill which has a lot of variation from day to day and shot to shot, the latter is just athletic ability with little day to day variation (excepting days where you just mishit everything, I suppose) If one of us tells the other we had a "good driving day" we mean we're hitting it more accurately, not suddenly hitting it 30 yards further than normal.
Back to your first question, it is obvious that there are some holes with a nice even fairway where no matter where I put my drive, if you ask me whether I can improve on it, so long as I'm allowed to move the ball closer to the hole I can always improve on it. I can improve it a yard at a time until you let me place it in the hole. Length is its own reward. But assuming you more reasonably restrict me to moving the ball no closer to the hole, there are some holes where it would make a real difference to my results, but also some holes where the difference would be impossible to measure no matter how many shots you had me hit from each location. I think this is self evident. You may be able to construct an argument for why a golfer should want to move the ball a few yards to the left or to the right from where he lays that makes sense in theory, but if it doesn't make any difference for him in practice, does it really matter? I think it does not.
I believe that there would be a lot of holes where some golfers feel the angle matters to them, and some golfers don't, simply due to the diversity in shot shape, trajectory, spin and intangibles like "fitting one's eye". Some like to fade it in, others prefer to run it in, some prefer to work it off the slopes, some prefer to stick it where they want it, etc. I think the set of holes where angle matters is going to be different for different golfers for this reason, and also the percentage of holes where the angle matters. For a hacker and for Rory, there probably aren't many holes where the angle matters, due to the complete lack of skill for one and the complete supremacy of skills for the other. For guys who look at golf courses as a series of approach angles and like to work the ball on every shot, there may be very few holes where the angle does not matter.
You may be viewing it from the latter perspective. I'm probably stepping into a real minefield saying this on GCA, but I think people here enjoy architecture so much that they far too often overrate the importance of angle of approach. Yes, it does matter, a lot, on many great holes. But I see this discussion even on holes where I think it only matters inside someone's head (not to discount that, most golf is played there so if you think it matters to you then it does matter to you) I can't help wondering however, were it possible to conduct a blind test, what percentage of holes where people think angles matter to them that they really don't if the mental effect could be controlled for...